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Patent 2480537 Summary

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(12) Patent: (11) CA 2480537
(54) English Title: DOWNHOLE FORCE GENERATOR AND METHOD FOR USE OF SAME
(54) French Title: GROUPE MOTEUR POUR FOND DE TROU ET METHODE D'UTILISATION
Status: Deemed expired
Bibliographic Data
(51) International Patent Classification (IPC):
  • E21B 23/00 (2006.01)
  • E21B 31/00 (2006.01)
  • E21B 41/00 (2006.01)
(72) Inventors :
  • CLEMENS, JACK G. (United States of America)
  • MOORE, DARRELL W. (United States of America)
  • CAMPBELL, MICHAEL (United States of America)
(73) Owners :
  • HALLIBURTON ENERGY SERVICES, INC. (United States of America)
(71) Applicants :
  • HALLIBURTON ENERGY SERVICES, INC. (United States of America)
(74) Agent: NORTON ROSE FULBRIGHT CANADA LLP/S.E.N.C.R.L., S.R.L.
(74) Associate agent:
(45) Issued: 2013-05-28
(22) Filed Date: 2004-09-02
(41) Open to Public Inspection: 2005-03-15
Examination requested: 2009-08-19
Availability of licence: N/A
(25) Language of filing: English

Patent Cooperation Treaty (PCT): No

(30) Application Priority Data:
Application No. Country/Territory Date
10/662,797 United States of America 2003-09-15

Abstracts

English Abstract

A downhole force generator (60) adapted to be moved to a target location within a wellbore (70) for interaction with a well tool (74) previously positioned in the wellbore (70) comprises a downhole power unit (62) having a moveable shaft (68). An anchor (64) is operably associated with the downhole power unit (62). The anchor (64) has an anchoring configuration and a running configuration. In the anchoring configuration, the anchor (64) longitudinally secures the downhole force generator (60) within the wellbore (70). An operating tool (66) is operably associated with the downhole power unit (62) and is operably engageable with the well tool (74) such that when the operating tool (66) is operably engaged with the well tool (74) and the anchor (64) is in the anchoring configuration, movement of the moveable shaft (68) will transmit a force to the well tool (74).


French Abstract

Groupe moteur pour fond de trou (60) adapté pour être déplacé vers un endroit cible dans un trou de forage (70) afin d'interagir avec un outil de puits (74) préalablement placé dans le puits de forage (70) et comprenant un bloc-moteur de fond de trou (62) doté d'un arbre mobile (68). Un ancrage (64) est associé de façon fonctionnelle au bloc moteur de fond de trou (62). L'ancrage (64) présente une configuration d'ancrage et une configuration de fonctionnement. Selon la configuration d'ancrage, l'ancrage (64) fixe de façon longitudinale le groupe moteur pour fond de trou (60) dans le puits de forage (70). Un outil de fonctionnement (66) est associé de façon fonctionnelle au bloc moteur de fond de trou (62) est s'engage de façon fonctionnelle avec l'outil de puits (74) de façon à ce que l'outil de fonctionnement (66) soit engagé de façon fonctionnelle avec l'outil de puits (74) et à ce que l'ancrage (64) soit en configuration d'ancrage. Le mouvement de l'arbre mobile (68) transmettra alors une force à l'outil de puits (74).

Claims

Note: Claims are shown in the official language in which they were submitted.


What is claimed is:

1. A downhole force generator adapted to be moved to a target
location within a wellbore for interaction with a well tool
positioned in the wellbore, the downhole force generator
comprising: a downhole power unit having a moveable shaft, an
electric motor including a rotor, and a jackscrew assembly
including a rotational member connected to the rotor, the
rotational member operably associated with the moveable shaft
to impart motion thereto; an anchor operably associated with
the downhole power unit, the anchor operable between a
running configuration and an anchoring configuration wherein
the anchor longitudinally secures the downhole force
generator within the wellbore; and an operating tool operably
associated with the downhole power unit and operably
engageable with the well tool such that when the operating
tool is operably engaged with the well tool and the anchor is
in the anchoring configuration, movement of the moveable
shaft will transmit a force to the well tool.

2. The downhole force generator as recited in claim 1 wherein
the downhole power unit further comprises a self-contained
power source for providing electrical power.

3. The downhole force generator as recited in claim 1 wherein
the downhole power unit further comprises a controller that
controls the operation of the moveable shaft.

4. The downhole force generator as recited in claim 1 wherein
the running configuration of the anchor is a radially
contracted configuration, wherein the anchoring configuration
-28-

of the anchor is a radially expanded configuration and
wherein the anchor is operated therebetween in response to
movement of the moveable shaft.

5. The downhole force generator as recited in claim 1 wherein
the moveable shaft of the downhole power unit is
longitudinally moveable such that the downhole force
generator generates a longitudinal force on the well tool.

6. The downhole force generator as recited in claim 1 wherein
the moveable shaft of the downhole power unit is rotatably
moveable such that the downhole force generator generates a
rotary force on the well tool.

7. The dowuhole force generator as recited in claim 1 wherein
the anchor further comprises slips that mechanically engage
the wellbore in the radially expanded configuration of the
anchor.

8. The downhole force generator as recited in claim 1 wherein
the anchor further comprises a packing assembly that
substantially sealingly engages the wellbore in the radially
expanded configuration of the anchor.

9. The downhole force generator as recited in claim 1 wherein
the anchor further comprises a spring assembly that stores
energy when the anchor is in the radially expanded
configuration.

10. The downhole force generator as recited in claim 1
wherein the moveable shaft of the downhole power unit extends
-29-

through a longitudinal bore of the anchor to the operating
tool.

11. The downhole force generator as recited in claim 1
wherein the operating tool further comprises a shifting tool
for actuating the well tool from one operational state to
another operational state.

12. The downhole force generator as recited in claim 1
wherein the operating tool further comprises a pulling tool
for dislodging the well tool.

13. The downhole force generator as recited in claim 12
wherein the pulling tool further comprises a latching
assembly that engages the well tool.

14. The downhole force generator as recited in claim 12
wherein the pulling tool further comprises a fishing nose
that engages a fishing neck of the well tool.

15. A fishing tool adapted to be moved to a target location
within a wellbore for dislodging a well tool positioned in
the wellbore, the fishing tool comprising: a downhole power
unit having a moveable shaft, an electric motor including a
rotor, and a jackscrew assembly including a rotational member
connected to the rotor, the rotational member operably
associated with the moveable shaft to impart motion thereto;
an anchor operably associated with the downhole power unit,
the anchor operable between a running configuration and an
anchoring configuration wherein the anchor longitudinally
secures the downhole force generator within the wellbore; and

-30-

a pulling tool operably associated with the downhole power
unit and operably engageable with the well tool such that
when the pulling tool is operably engaged with the well tool
and the anchor is in the anchoring configuration, movement of
the moveable shaft will transmit a force to dislodge the well
tool.

16. The fishing tool as recited in claim 15 wherein the
downhole power unit further comprises a self-contained power
source for providing electrical power.

17. The fishing tool as recited in claim 15 wherein the
downhole power unit further comprises a controller that
controls the operation of the moveable shaft.

18. The fishing tool as recited in claim 15 wherein the
running configuration of the anchor is a radially contracted
configuration, wherein the anchoring configuration of the
anchor is a radially expanded configuration and wherein the
anchor is operated therebetween in response to movement of
the moveable shaft.

19. The fishing tool as recited in claim 15 wherein the
moveable shaft of the downhole power unit is longitudinally
moveable such that the fishing tool generates a longitudinal
force on the well tool.

20. The fishing tool as recited in claim 15 wherein the
moveable shaft of the downhole power unit is rotatably
moveable such that the fishing tool generates a rotary force
on the well tool.

-31-

21. The fishing tool as recited in claim 15 wherein the
anchor further comprises slips that mechanically engage the
wellbore in the radially expanded configuration of the
anchor.

22. The fishing tool as recited in claim 15 wherein the
anchor further comprises a packing assembly that
substantially sealingly engages the wellbore in the radially
expanded configuration of the anchor.

23. The fishing tool as recited in claim 15 wherein the
anchor further comprises a spring assembly that stores energy
when the anchor is in the radially expanded configuration.

24. The fishing tool as recited in claim 15 wherein the
moveable shaft of the downhole power unit extends through a
longitudinal bore of the anchor to the pulling tool.

25. A method for transmitting force to a well tool positioned
in the wellbore, the method comprising the steps of: running
a downhole force generator including a downhole power unit
having a moveable shaft, an anchor and an operating tool to a
target location downhole; longitudinally securing the
downhole force generator within the wellbore by operating the
anchor from a radially contracted configuration to a radially
expanded configuration in response to movement of the
moveable shaft; operably engaging the well tool with the
operating tool; and transmitting a force to the well tool
with the operating tool in response to movement of the
moveable shaft.

-32-

26. The method as recited in claim 21 wherein the step of
running a downhole force generator to a target location
downhole further comprises running the downhole force
generator to a target location downhole on a conveyance.

27. The method as recited in claim 26 wherein the step of
running the downhole force generator to a target location
downhole on a conveyance further comprises the step of
selecting the conveyance from the group consisting of a
wireline, a slickline, an electric line, a coiled tubing and
a jointed tubing.

28. The method as recited in claim 25 wherein the step of
operating an anchor between a radially contracted
configuration and a radially expanded configuration further
comprises mechanically engaging slips with the wellbore.

29. The method as recited in claim 25 wherein the step of
operating an anchor between a radially contracted
configuration and a radially expanded configuration further
comprises substantially sealingly engaging a packing assembly
with the wellbore.

30. The method as recited in claim 25 wherein the step of
operably engaging the well tool with the downhole force
generator further comprises operably engaging the well tool
with a pulling tool.

31. The method as recited in claim 25 wherein the step of
operably engaging the well tool with the downhole force

-33-

generator further comprises operably engaging the well tool
with a shifting tool.

32. The method as recited in claim 25 wherein the step of
transmitting a force to the well tool with the downhole force
generator further comprises transmitting a longitudinal force
to the well tool.

33. The method as recited in claim 25 wherein the step of
transmitting a force to the well tool with the downhole force
generator further comprises transmitting a rotary force to
the well tool.

34. The method as recited in claim 25 wherein the step of
transmitting a force to the well tool with the downhole force
generator further comprises actuating the well tool from one
operational state to another operational state.

35. The method as recited in claim 25 wherein the step of
transmitting a force to the well tool with the downhole force
generator further comprises dislodging the well tool.

36. The method as recited in claim 25 wherein the step of
longitudinally securing the downhole force generator within
the wellbore occurs prior to the step of operably engaging
the well tool with the downhole force generator.

37. The method as recited in claim 25 wherein the step of
longitudinally securing the downhole force generator within
the wellbore occurs after the step of operably engaging the
well tool with the downhole force generator.

-34-

38. A method for dislodging a well tool positioned in the
wellbore, the method comprising the steps of: running a
fishing tool including a downhole power unit having a
moveable shaft, an anchor and an operating tool to a target
location downhole; longitudinally securing the fishing tool
within the wellbore by operating the anchor from a radially
contracted configuration to a radially expanded configuration
in response to movement of the moveable shaft; operably
engaging the well tool with the operating tool; and
dislodging the well tool by applying a force to the well tool
with the operating tool in response to movement of the
moveable shaft.

39. The method as recited in claim 38 wherein the step of
running a fishing tool to a target location downhole further
comprises running the fishing tool to a target location
downhole on a conveyance.

40. The method as recited in claim 39 wherein the step of
running the fishing tool to a target location downhole on a
conveyance further comprises the step of selecting the
conveyance from the group consisting of a wireline, a
slickline, an electric line, a coiled tubing and a jointed
tubing.

41. The method as recited in claim 38 wherein the step of
operating an anchor between a radially contracted
configuration and a radially expanded configuration further
comprises mechanically engaging slips with the wellbore.


-35-

42. The method as recited in claim 38 wherein the step of
operating an anchor between a radially contracted
configuration and a radially expanded configuration further
comprises substantially sealingly engaging a packing assembly
with the wellbore.

43. The method as recited in claim 38 wherein the step of
dislodging the well tool from the wellbore further comprises
transmitting a longitudinal force to the well tool.

44. The method as recited in claim 38 wherein the step of
dislodging the well tool from the wellbore further comprises
transmitting a rotary force to the well tool.

45. The method as recited in claim 38 wherein the step of
longitudinally securing the fishing tool within the wellbore
occurs after the step of operably engaging the well tool with
the fishing tool.

46. The method as recited in claim 38 wherein the step of
longitudinally securing the fishing tool within the wellbore
occurs prior to the step of operably engaging the well tool
with the fishing tool.

47. A downhole force generator adapted to be moved to a
target location within a wellbore for interaction with a well
tool positioned in the wellbore, the downhole force generator
comprising: a downhole power unit having a moveable shaft; an
anchor operably associated with the downhole power unit, the
anchor operable between a running configuration and an
anchoring configuration in response to movement of the
-36-

moveable shaft, in the anchoring configuration, the anchor
longitudinally securing the downhole force generator within
the wellbore, the moveable shaft of the downhole power unit
extending through a longitudinal bore of the anchor; and an
operating tool operably associated with the moveable shaft of
the downhole power unit and operably engageable with the well
tool such that when the operating tool is operably engaged
with the well tool and the anchor is in the anchoring
configuration, movement of the moveable shaft will transmit a
force to the well tool via the operating tool.

48. The downhole force generator as recited in claim 47
wherein the downhole power unit further comprises a self-
contained power source for providing electrical power.

49. The downhole force generator as recited in claim 47
wherein the downhole power unit further comprises: an
electric motor including a rotor; and a jackscrew assembly
including a rotational member connected to the rotor, the
rotational member operably associated with the moveable shaft
to impart motion thereto.

50. The downhole force generator as recited in claim 47
wherein the downhole power unit further comprises a
controller that controls the operation of the moveable shaft.

51. The downhole force generator as recited in claim 47
wherein the moveable shaft of the downhole power unit is
longitudinally moveable such that the downhole force
generator generates a longitudinal force on the well tool.


-37-

52. The downhole force generator as recited in claim 47
wherein the moveable shaft of the downhole power unit is
rotatably moveable such that the downhole force generator
generates a rotary force on the well tool.

53. The downhole force generator as recited in claim 47
wherein the anchor further comprises slips that mechanically
engage the wellbore in the radially expanded configuration of
the anchor.

54. The downhole force generator as recited in claim 47
wherein the anchor further comprises a packing assembly that
substantially sealingly engages the wellbore in the radially
expanded configuration of the anchor.

55. The downhole force generator as recited in claim 47
wherein the anchor further comprises a spring assembly that
stores energy when the anchor is in the radially expanded
configuration.

56. The downhole force generator as recited in claim 47
wherein the operating tool further comprises a shifting tool
for actuating the well tool from one operational state to
another operational state.

57. The downhole force generator as recited in claim 47
wherein the operating tool further comprises a pulling tool
for dislodging the well tool.

58. The downhole force generator as recited in claim 57
wherein the pulling tool further comprises a latching

-38-

assembly that engages the well tool.

59. The downhole force generator as recited in claim 57
wherein the pulling tool further comprises a fishing nose
that engages a fishing neck of the well tool.



-39-

Description

Note: Descriptions are shown in the official language in which they were submitted.



CA 02480537 2004-09-02
DOWNHOLE FORCE GENERATOR AND METHOD FOR USE OF SAME
TECHNICAL FIELD OF THE TNVENTION
(0001] This invention relates, in general, to a downhole
force generator and, in particular, to a downhole force
generator that is anchored at a target location in a well
and operably associated with a downhole tool previously
positioned in the well then operated to exert a longitudinal
or rotary force on the downhole tool.
BACKGROUND OF THE INVENTION
[0002] Without limiting the scope of the present
invention, its background will be described with reference
to using a pulling tool for retrieving a well tool that was
previously located within a well, as an example.
[0003] After drilling a well that intersects a
subterranean hydrocarbon bearing reservoir, a variety of
well tools are often positioned in the wellbore during
completion, production or remedial activities. For example,
temporary packers are often set in the wellbore during the
completion and production operating phases of the well. Iri
addition, various operating tools including flow controllers
such as plugs, chokes, valves and the like and safety
devices such as safety valves are often releasably
positioned in the wellbore.
[0004] In the event that one of thesa well tools that has
been previously placed within the wellbore requires removal,
a pulling tool attached to a conveyance such as a wireline,
slickline, coiled tubing or the like is typically run
downhole to the location of the well tool to be removed.
The pulling tool, which may include a fishing nose and
latching assembly, is latched to a fishing neck on the well
- 1 -


CA 02480537 2004-09-02
tool previously placed into the wellbore. Thereafter, the
well tool can be dislodged from the wellbore and retrieved
to the surface.
[0005] It. has been found, however, the once a well tool
has been positioned within the wellbore, the well tool may
become stuck in the wellbore and therefore difficult to
retrieve. In addition, even normal retrieval operation may
place significant demands on the integrity and strength of
the pulling tool and conveyance in wells that are deep,
IO deviated, inclined or horizontal due to elongation of the
conveyance and added frictional effects.
[0006] Accordingly, prior art pulling tools and
conveyances can apply only a limited amount of pull force to
dislodge a well tool previously placed into the wellbore.
Therefore, a need has arisen for a pulling tool that will
provide for the exertion of a greater pulling force such
that well tools that are stuck within the wellbore can be
retrieved. A need has also arisen for such a pulling tool
that will produce the necessary force to retrieve well tools
from deep, deviated, inclined or horizontal wellbores.
SUMMARY OF THE INVENTION
[0007] The present invention disclosed herein comprises a
downhole force generator and a method for using the downhole
force generator that are capable of providing sufficient
force to dislodge a well tool that is stuck within the
wellbore. The downhole force generator of the present
invention will also produce the necessary force to retrieve
well tools from deep, deviated, inclined or horizontal
wellbores. In addition, the downhole force generator of the
present invention may be used to actuate well tools from 'one
- 2 -


CA 02480537 2004-09-02
operational state to another operational state even if the
well tool has become stuck in its present operational state.
[0008] The downhole force generator of the present
invention is adapted to be moved to a target location within
a wellbore for interaction with a well tool that was
previously positioned within the wellbore. The well tool
may be any type of well tool positioned downhole requiring
intervention of some type including shifting, actuation,
repositioning, retrieval or the like. The well tool may be
in a desired or known location downhole or in an undesired
or unknown location downhole in the case of certain fishing
operations. The downhole force generator includes a
downhole power unit having a moveable shaft. An anchor is
operably associated with the downhole power unit. The
anchor is operable between a radially contracted
configuration or running configuration and a radially
expanded configuration or anchoring configuration. The
anchor is operated between these positions in response to
movement of the moveable shaft of the downhole power unit.
In the radially expanded configuration, the anchor
longitudinally secures the downhole force generator within
the wellbore. An operating tool is also operably associated
with the downhole power unit. The operating tool operably
engages the well tool such as by latching into the well
tool, contacting the well tool or being positioned relative
to the well tool to enable interaction between the operating
tool and the well tool. When the operating tool is operably
engaged with the well tool and the anchor is in the
anchoring configuration, movement of the moveable shaft will
transmit a force to the well tool.
[0009] In one embodiment, the downhole power unit
includes a self-contained power source for providing
- 3 -


CA 02480537 2004-09-02
electrical power. Additionally, the downhole power unit may
include an electric motor including a rotor and a jackscrew
assembly including a rotational member connected to the
rotor. The rotational member is operably associated with
the moveable shaft to impart motion thereto. The moveable
shaft of the downhole power unit may be longitudinally
moveable such that the downhole force generator generates a
longitudinal force on the well tool. Alternatively or
additionally, the moveable shaft may be rotatably moveable
such that the downhole force generator generates a torsional
force on the well tool.
[0010] In one embodiment, the anchor of the downhole
force generator of the present invention includes barrel
slips that mechanically engage the wellbore when the anchor
is in the radially expanded configuration. In another
embodiment, the anchor includes a packing assembly that
sealingly engages the wellbore when the anchor is in the
radially expanded configuration. In yet another embodiment,
the anchor includes a spring assembly that stores energy
when the anchor is in the radially expanded. configuration.
[0011] In one embodiment, the operating tool of the
downhole force generator of the present invention is a
shifting tool for actuating the well tool from one
operational state to another operational state. In another
embodiment, the operating tool is a pulling tool for
dislodging the well tool from the wellbore. In this
embodiment, the pulling tool may include a latching assembly
that engages the well tool and a fishing nose that engages a
fishing neck of the well tool.
[0012] In another aspect, the present invention is
directed to a fishing tool adapted to be moved to a target
- 4 -


CA 02480537 2004-09-02
location within a wellbore for retrieving a well tool
previously positioned in the wellbore. The fishing tool
includes a downhole power unit having a moveable shaft, an
anchor operably associated with the downhole power unit that
is operable between a running configuration and an anchoring
configuration wherein the anchor longitudinally secures the
fishing tool within the wellbore and a pulling tool operably
associated with the downhole power unit and operably
engageable with the well tool such that when the operating
tool is operably engaged with the well tool and the anchor
is in the anchoring configuration, movement of the moveable
shaft will transmit a force to dislodged the well tool from
the wellbore.
[0013] In a further aspect, the present invention is
directed to a method for transmitting force to a well tool
previously positioned in the wellbore. The method includes
the steps of running a downhole force generator to a target
location downhole, longitudinally securing the downhole
force generator within the wellbore, operably engaging the
well tool with the downhole force generator and transmitting
a force to the well tool with the downhole force generator:
[0014] In yet another aspect, the present invention is
directed to a method for retrieving a well tool previously
positioned in the wellbore. The method includes the steps
of running a fishing tool to a target location downhole,
longitudinally securing the fishing tool within the
wellbore, operably engaging the well tool with the fishing
tool and dislodging the well tool from the wellbore by
applying a force to the well tool with the fishing tool.
- 5 -


CA 02480537 2004-09-02
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a more complete understanding of the features
and advantages of the present invention, reference is now
made to the detailed description of the invention along with
the accompanying figures in which corresponding numerals in
the different figures refer to corresponding parts and in
which:
[0016] Figure 1 is a schematic illustration of an
offshore oil and gas platform operating a downhole force
generator according to the present invention;
[0017] Figure 2 is a block diagram of a downhole force
generator according to the present invention operating to
retrieve a well tool that was previously positioned in a
wellbore;
[0018] Figure 3 is a block diagram of a downhole force
generator according to the present invention operating to
actuate a well tool positioned in a wellbore;
[0019] Figures 4-6 are quarter sectional views of
successive axial sections of one embodiment of a downhole
power unit of a downhole force generator according to the
present invention;
[0020] Figure 7 is a quarter sectional view of one
embodiment of an anchor of a. downhole force generator
according to the present invention; and
[0021] Figure 8 is a quarter sectional view of one
erilbodiment of a pulling tool of a downhole force generator
according to the present invention.
- 6 -


CA 02480537 2004-09-02
DETAILED DESCRIPTION OF THE INVENTION
[0022] While the making and using of. various embodiments
of the present invention are discussed in detail below, it
should be appreciated that the present invention provides
many applicable inventive concepts which can be embodied in
a wide variety of specific contexts. The specific
embodiments discussed herein are merely illustrative of
specific ways to make and use the invention, and do not
delimit the scope of the present invention.
[0023] Referring initially to figure 1, a downhole force
generator of the present invention is being operated from an
offshore oil and gas platform that is schematically
illustrated and generally designated 10. A semi-submersible
platform 12 is centered over a submerged oil and gas
formation 14 located below sea floor 16. A subsea conductor
18 extends from deck 20 of platform 12 to sea floor 16. A
wellbore 22 extends from sea floor 16 anal traverse formation
14. Wellbore 22 includes a casing 24 that is cemented
therein by cement 26. Casing 24 has perforations 28 in the
interval proximate formation 14.
[0024] A tubing string 30 extends from wellhead 32 to
formation 14 to provide a conduit for production fluids to
travel to the surface. A pair of packers 34, 36 provide a
fluid seal between tubing string 30 and casing 24 and direct
the flow of production fluids from formation 14 through sand
control screen 38. Disposed within tubing string 30 is a
well tool 40 such as a wireline retrievable subsurface
safety valve that is designed to shut in the flow of
production fluids if certain out of range conditions occur.
In the illustrated embodiment, a fishing operation is being
conducted wherein a downhole force generator 42 is being run


CA 02480537 2004-09-02
downhole on a conveyance 44, such as a wireline, a
slickline, an electric line, a coiled tubing and a jointed
tubing or the like. As explained in greater detail below,
downhole force generator 42 includes a downhole power unit
46, an anchor 48 and an operating tool 50. Operating tool
50 may be a pulling tool, a shifting tool or other tool
capable of interaction with well tool 40
[0025] For example, operating tool 50 may be a shifting
tool designed to actuate well tool 40 from one operational
state to another operational state. As those skilled in the
art will understand, if well tool 40 becomes stuck in one of
its operational states, the force required to shift well
tool 40 to another of its operational states may be high and
may exceed the force which can be applied thereto by
conventional wireline shifting tools. Downhole force
generator 42 of the present invention, however, can be used
to apply the required force to shift well tool 40 from its
stuck operational state to its desired operational state.
This is achieved by deploying downhole force generator 42 to
the target location, anchoring downhole force generator 42
within tubing string 30 with anchor 48, engaging well tool
40 with operating tool 50 and applying a longitudinal or
rotational force to well tool 40 with downhole power unit
46, thereby operating well tool 40 from its stuck
operational state to its desired operational state.
[0026] Similarly, if operating tool 50 is a pulling tool,
downhole force generator 42 is capable of providing
sufficient force to dislodge well tool 40 from wellbore 22
even if well tool 40 has become stuck within wellbore 22.
Specifically, downhole force generator 42 will produce the
necessary force to retrieve well tools from deep, deviated,
inclined or horizontal wellbores. Accordingly, even though
_ g _


CA 02480537 2004-09-02
figure 1 depicts a vertical well, it should be noted by one
skilled in the art that the downhole force generator of the
present invention is equally well-suited for use in deviated
wells, inclined wells or horizontal wells. As such, the use
of directional terms such as above, below, upper, lower,
upward, downward and the like are used in relation to the
illustrative embodiments as they are depicted in the
figures, the upward direction being toward the top of the
corresponding figure and the downward direction being toward
the bottom of the corresponding figure. Also, even though
figure 1 depicts an offshore operations it should be noted
by one skilled in the art that the downhole force generator
of the present invention is equally well-suited for use in
onshore operations.
[0027] Referring now to figure 2, therein is
schematically depicted a downhole force. generator of the
present invention that is generally designated 60. Downhole
force generator 60 includes a downhole power unit 62, an
anchor 64 and a pulling tool 66, each of which will be
discussed in greater detail below. Downhole power unit 62
has a moveable member described herein as a moveable shaft
68 that is operably associated with and extends through
anchor 64 and that couples to pulling tool 66. Downhole
force generator 60 is illustrated as having been lowered
into a well 70 on a conveyance 72 such as a wireline, a
slickline, coiled tubing, jointed pipe or other tubing
string.
[0028] In the illustrated embodiment, downhole force
generator 60 has reached its target location in well 70 and
has engaged a well tool 74. Well tool 74 is not part of the
present invention but rather is the workpiece operated upon
by the invention. As such, well tool 74 can be any device
_ g _


CA 02480537 2004-09-02
that has been previously positioned in well 70 or any device
that has become a fish within well 70 and is adapted to
receive or be engaged by downhole force generator 60.
Examples of particular well tools 74 include plugs, locks,
chokes, valves and others devices used in any of the various
operations of drilling, testing, completing or producing
well 70.
[0029] Either prior to or after, downhole force generator
60 has engaged well tool 74, downhole force generator 60 is
longitudinally secured within well 70 by operating anchor
64. As explained in greater detail below, anchor 64 is
operated from its running position to its anchoring position
using downhole power unit 62. Specifically, downhole power
unit 62 transmits a longitudinal force to anchor 64 via
moveable shaft 68 such that anchoring slips engage the inner
surface of well 70, thereby longitudinally securing downhole
force generator 60 within well 70. Once downhole force
generator 60 is longitudinally secured and has engaged well
tool 74, operation of moveable shaft 68 of downhole power
unit 62 transmits a longitudinal force to well tool 74 such
that well tool 74 is dislodged from well 70. After well
tool 74 is free, anchor 64 can be released from well 70 such
that downhole force generator 60 along with well tool 74 can
be retrieved to the surface.
[0030] As will be described in more detail below, a
particular implementation of downhole power unit 62 includes
an elongated housing, a motor disposed in the housing and a
sleeve connected to a rotor of the motor. The sleeve is a
rotational member that rotates with the rotor. A moveable
member such as moveable shaft 68 is received within the
threaded interior of the sleeve. Operation of the motor
rotates the sleeve which causes the moveable shaft 68 to
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CA 02480537 2004-09-02
move longitudinally. Accordingly, when downhole power unit
62 is longitudinally fixed within well 70 and the moveable
member is operably associated with well tool 74, . a
longitudinal force is applied to well tool 74.
Alternatively or additionally, the moveable member could
operate as a rotational member such that torque is
transmitted between downhole power unit 62 and well tool 74.
[0031] Preferably, a microcontroller made of suitable
electrical components to provide miniaturization and
durability within the high pressure, high temperature
environments which can be encountered in an oil or gas well
is used to control the operation of downhole power unit 62.
The microcontroller is preferably housed within the
structure of downhole power unit 62, it can, however, be
connected outside of downhole power unit 62 but within the
tool string moved into well 70. I:n whatever physical
location the microcontroller is disposed, it is
operationally connected to downhole power unit 62 to actuate
movement of the moveable member when desired. In one
embodiment, the microcontroller includes a microprocessor
which operates under control of a timing device arid a
program stored in a memory. The program in the memory
includes instructions which cause the microprocessor to
control the downhole power unit 62.
[0032] The microcontroller operates under power from a
power supply which can be at the surface of the well or,
preferably, contained within the microcontroller, downhole
power unit 62 or otherwise within a downhole portion of the
tool string of which these components are a part. For a
particular implementation, the power source provides the
electrical power to both the motor of downhole power unit 62
and the microcontroller. When downhole power unit 62 is at
- 11 -


CA 02480537 2004-09-02
the target location, the microcontroller commences operation
of downhole power unit 62 as programmed. For example, with
regard to controlling the motor that operates the sleeve
receiving the moveable member, the microcontroller sends a
command to energize the motor to rotate the sleeve in the
desired direction to either extend or retract the moveable
member at the desired speed. One or more sensors monitor
the operation of downhole power unit 62 and provide
responsive signals to the microcontroller. When the
microcontroller determines that a desired result has been
obtained, it stops operation of downhole power unit 62, such
as. by de-energizing the motor of the exemplified
implementation.
[0033] Referring now to figure 3, therein is
schematically depicted another embodiment of a downhole
force generator of the present invention that is generally
designated 80. Downhole force generator 80 includes a
downhole power unit 82, an anchor 84 and a shifting tool 86.
Downhole power unit 82 has a moveable member described
herein as a moveable shaft 88 that is operably associated
with and extends through anchor 84 and that couples to
shifting tool 86. Downhole force generator 80 is
illustrated as having been lowered into a well 90 on a
conveyance 92. In the illustrated embodiment, downhole
force generator 80 has reached its target location in well
90 and has engaged a well tool 94. As stated above, the
well tool is not part of the present invention but rather is
the workpiece operated upon by the invention. In the
illustrated embodiment, well tool 94 it can be any device
that is positioned in well 90 that may be actuated from one
operating position to another by translational or rotational
motion. Examples of particular wel l tools 94 include
chokes, valves, sliding sleeves and the like used in any of
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CA 02480537 2004-09-02
the various operations of drilling, testing, completing or
producing well 90.
[0034] Either prior to or after, downhole force generator
80 has engaged well tool 94, downhole force generator 80 is
longitudinally secured within well 90 by operating anchor
84. Once downhole force generator 80 is longitudinally
secured and has engaged well tool 94, operation of moveable
shaft 88 of downhole power unit 82 transmits a longitudinal
or rotational force to well tool 94 such that well tool 94
is actuated from one operating position to another. After
well tool 94 is actuated, anchor 84 can be released from
well 90 such that downhole force generator 80 can be
retrieved to the surface.
[0035] Referring next to figures 4-6, therein is depicted
successive axial sections of an exemplary downhole power
unit that is generally designated 100 and that is capable of
operations in the downhole force generator of the present
invention. Downhole power unit 100 includes a working
assembly 102 and a power assembly 104. Power assembly 104
includes a housing assembly 106 which comprises suitably
shaped and connected generally tubular housing members. An
upper portion of housing assembly 106 includes an
appropriate mechanism to facilitate coupling of housing 106
to a conveyance 108. Housing assembly 106 also includes a
clutch housing 110 as will be described in more detail
below, which forms a portion of a clutch assembly 112.
[0036] In the illustrated embodiment, power assembly 104
includes a self-contained power source, eliminating the need
for power to be supplied from an exterior source, such as a
source at the surface. A preferred power source comprises a
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CA 02480537 2004-09-02
battery assembly 114 which may include a pack of twenty to
sixty alkaline or lithium batteries.
[0037] Connected with power assembly 104 is the force
generating and transmitting assembly. The force generating
and transmitting assembly of this implementation includes a
direct current (DC) electric motor 116, coupled through a
gearbox 118, to a jackscrew assembly 120. A plurality of
activation mechanisms 122, 124 and 126, as will be
described, can be electrically coupled between battery
assembly 114 and electric motor 116. Electric motor 116 may
be, of any suitable type. One example is a motor operating
at 7500 revolutions per minute (rpm) in unloaded condition,
and operating at approximately 5000 rpm in a loaded
condition, and having a horsepower rating of approximately
1/30th of a horsepower. In this implementation, motor 116
is coupled through the gearbox 118 which provides
approximately 5000:1 gear reduction. Gearbox 118 is coupled
through a conventional drive assembly 128 to jackscrew
assembly 120.
[003$] The jackscrew assembly 120 includes a threaded
shaft 130 which moves longitudinally, rotates or both, in
response to rotation of a sleeve assembly 132. Threaded
shaft 130 includes a threaded portion 134, and a generally
smooth, polished lower extension 136. Threaded shaft 130
further includes a pair of generally diametrically opposed
keys 138 that cooperate with a clutch block 140 which is
coupled to threaded shaft 130.
[0039] Clutch housing 110 includes a pair of
diametrically opposed keyways 142 which extend along at
least a portion of the possible length of travel. Keys 138
extend radially outwardly from threaded shaft 130 through
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CA 02480537 2004-09-02
clutch block 140 to engage each ~of keyways 142 in clutch
housing 110, thereby selectively preventing rotation of
threaded shaft 130 relative to housing 110.
[0040, Rotation of sleeve assembly 132 in one direction
causes threaded shaft 130 and clutch block 140 to move
longitudinally upwardly relative to housing assembly 110 if
shaft 130 is not at its uppermost limit. Rotation of the
sleeve assembly 132 in the opposite direction moves shaft
130 downwardly relative to housing 110 if shaft 130 is not
at its lowermost position. Above a certain level within
clutch housing 110, as indicated generally at 144, clutch
housing 110 includes a relatively enlarged internal diameter
bore 146 such that moving clutch block 140 above level 144
removes the outwardly extending key 138 from being
25 restricted from rotational movement. Accordingly,
continuing rotation of sleeve assembly 132 causes
longitudinal movement of threaded shaft 130 until clutch
block 140 rises above level 144, at which point rotation of
sleeve assembly 132 will result in free rotation of threaded
shaft 130. By virtue of this, clutch assembly 112 serves as
a safety device to prevent burn-out o.f the electric motor,
and also serves as a stroke limiter. In a similar manner,
clutch assembly 112 may allow threaded shaft 130 to rotation
freely during certain points in the longitudinal travel of
threaded shaft 130.
[0041) In the illustrated embodiment, downhole power unit
100 incorporates three discrete activation assemblies,
separate from or part of the microcontroller discussed
above. The activation assemblies enable jackscrew 120 to
operate upon the occurrence of one or more predetermined
conditions. One depicted activation assembly is timing
circuitry 122 of a type known in the art. Timing circuitry
15 -


CA 02480537 2004-09-02
122 is adapted to provide a signal to the microcontroller
after passage of a predetermined amount of time. Further,
downhole power unit 100 can include an activation assembly
including a pressure-sensitive switch 124 of a type
generally known in the art which will provide a control
signal once the switch 124 reaches a depth at which it
encounters a predetermined amount of hydrostatic pressure
within the tubing string. Still further, downhole power
unit 100 can include an motion sensor 126, such as an
accelerometer or a geophone that is sensitive to vertical
motion of downhole power unit 100. Accelerometer 126 can be
combined with timing circuitry 122 such that when motion is
detected by accelerometer 126, timing circuitry 122 is
reset: Tf so configured, the activation assembly operates
to provide a control signal after accelerometer 126 detects
that downhole power unit 100 has remained substantially
motionless within the well for a predetermined amount of
time.
[0042] Working assembly 102 includes an actuation
assembly 148 which is coupled through housing assembly 106
to be movable therewith. Actuation assembly 148 includes an
outer sleeve member 150 which is threadably coupled at 152
to housing assembly 106. Working assembly 102 also includes
a connecting sub 154 which is releasably coupled at threaded
connection 156 to a portion of polished extension 136 of
threaded shaft 130 which allows for the disconnection of
threaded shaft 130 from connecting sub 154 upon application
of a predetermined axial force. Connecting sub 154
facilitates connecting downhole power unit 100 to an anchor
as will be described below. Specifically, connecting sub
154 is coupled to the anchor through pins 160 and collet
member 162.
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CA 02480537 2004-09-02
[0043] Threaded shaft 130 includes a radially enlarged
region 164 that interacts with collet member 162 when it is
desired to release the anchor from the well as will be
described below. Threaded shaft 130 also includes a
radially enlarged region 166 having locating keys 168 that
interacts with the anchor when it is desired to release the
anchor from the well as will be described below. The lower
end 170 of threaded shaft 130 has a threaded coupling that
allows for the coupling of downhole power unit 100 to an
operating tool such as a pulling tool as will be described
below or a shifting tool.
[0044) Even though a particular embodiment of a downhole
power unit has been depicted and described, it should be
clearly understood by those skilled in the art that other
types of downhole power devices could alternatively be used
with the downhole force generator of the present invention
such that the downhole force generator of the present
invention may exert a force on a well tool positioned within
the wellbore.
[0045] Referring now to figure 7, therein is shown an
exemplary anchor that is generally designated 180 and that
is capable of operations in the downhole force generator of
the present invention. It should be noted that threaded
shaft 130 of downhole power unit 100 passes through a rental
bore of anchor 180 as will be described in greater detail
below. Anchor 180 has a support mandrel assembly 182, which
supports a barrel slip assembly 184. Barrel slip assembly
184 is operable between a reduced diameter condition by
which anchor 180 may be placed into or removed from a
tubular string and an expanded diameter condition by which
barrel slip assembly 184 is set and mechanically engages the
tubular string such that the force generating tool of the
- 17 -


CA 02480537 2004-09-02
present invention is longitudinally secured within the
tubular string. In the illustrated embodiment, anchor 180
also includes a packing assembly 186 which is also movable
between a relatively reduced diameter condition, and a
relatively expanded diameter condition whereby packing
assembly 186 sealingly engages the interior of the tubular
string.
[0046] Barrel slip assembly 184 preferably includes a
one-piece slip body 188 which surrounds a portion of anchor
180 in a c.ircumferentially continuous manner, such that slip
body 188 is unbroken at any point around the anchor 180.
Slip body 188 comprises a plurality of anchoring slips 190
which are configured to be radially expansible. Each
anchoring slip 190 is preferably provided with opposing sets
of anchoring teeth 192, 194 upon longitudinally opposed
portions of its exterior surface which are adapted to
mechanically engage the interior surface of a tubular string
when barrel slip assembly 184 is set. Opposed anchoring
teeth 192, 194 are each directional to resist axial movement
of anchor 180, within the tubular string in either axial
direction.
[0047] Barrel slip assembly 184 further includes an
actuation assembly which includes upper and lower annular
wedge assemblies 196, 198 which are adapted to be
longitudinally movable relative to each other along. an outer
mandrel 200. Slip body 188 is configured to engage and
cooperate with wedge assemblies 196, 198 in such a manner
that converging longitudinal movement of annular wedge
assemblies 196, 198 causes radial expansion of slip body 188
by urging anchoring slips 190 radially outwardly.
- 18 -


CA 02480537 2004-09-02
[0048 Annular packing assembly 186 has a substantially
elastomeric sleeve 202 which is also operable .between an
expanded diameter condition and a reduced diameter condition
by virtue of axial compression. Annular packing assembly
186 is concentrically disposed relative to outer mandrel 200
of support mandrel assembly 182, and is disposed at a
relatively uphole position relative to barrel slip assembly
184. Compressional force may be applied to elastomeric
sleeve 202 between annular wedge assembly 196 and retaining
member 204.
[0049] Outer mandrel 200 of anchor 180 extends through
barrel slip assembly 184 and packing assembly 186 in a
generally coaxial relation therewith. A generally annular
engagement member 206 is attached by a threaded coupling
208, or other attachment mechanism, to outer mandrel 200
proximate the upper end thereof. Engagement member 206 is
adapted to be coupled the downhole power unit 100 described
above via its connecting sub 154 and specifically, through
pins 160 and collet member 162 of connecting sub 154 of
downhole power unit 100.
[0050] The actuation assembly of anchor 180 includes an
axial compression member 210 that is disposed around an
upper portion of outer mandrel 200. Axial compression
member 210 defines a radially extending actuation surface
212 which engages outer sleeve membe r 150 of actuation
assembly 148 downhole power unit 100. One or more shear
pins 214 are provided to resist motion of compression member
210 with respect to mandrel 200. A motion restricting
assembly 216 is operatively coupled to axial compression
member 210 to allow movement of axial compression member 210
in only a downward direction relative to outer mandrel 200.
In the illustrated embodiment, motion restriction assembly
- 19 -


CA 02480537 2004-09-02
216 includes a threaded ring 218 and a split-ring 220 which
associate axial compression member 210 with outer mandrel
200.
[0051] Split ring 220 is adapted to be movable axially
along mandrel 200 during setting of anchor 180 and will
engage recess 222 of outer mandrel 200 during removal
operations. Engagement of split ring 220 with annular
recess 222 provides a positive lock of compression member
210 relative to outer mandrel 200.
[0052] Anchor 180 further includes a release mandrel
assembly 224 disposed within outer mandrel 200 in a
generally coaxial relation therewith. One or more shear
pins 226 may be placed through portions of release mandrel
assembly 224 and outer mandrel 200 to resist axial
displacement between the mandrels. Release mandrel assembly
224 is axially extensible in response to diverging axial
tension applied proximate its axial ends. In a preferred
embodiment, release mandrel 224 includes an upper section
228 and a lower section 230, which are coupled to one
another by a selectively releasable connection, such as a
threaded connection 232. Releasable threaded connection 232
is configured to release under diverging axial tension of a
generally predetermined magnitude applied across upper
section 228 and lower section 230 of release mandrel
assembly 224, such that the sections separate and become
axially spaced from each other. In this preferred
embodiment, releasable threaded connection 232 is formed
through use of a plurality of threaded collet fingers 234 in
lower section 230 of release mandrel assembly 224. Other
extensible designs for release mandrel 224 may, of course be
contemplated, such as shearable telescoping configurations.
- 20 -


CA 02480537 2004-09-02
[0053] A threaded connection 236 may also be provided
between collet fingers 234 on lower half 230 of release
mandrel assembly 224 and outer mandrel 200. Threaded
connection 236 is adapted to maintain a fixed relation
between lower section 230 and outer mandrel 200 when upper
and lower sections 228, 230 are engaged. Threaded
connection 236 will also be severable under divergent axial
tension as upper and lower sections 228, 230 are separated.
[0054] Upper releasable mandrel section 228 includes an
internal generally annularly extending actuation surface 238
proximate its upper end. Similarly, lower releasable
mandrel section 230 includes an internal, generally annular,
actuation surface 240. Annular actuation surfaces 238, 240
on upper and lower releasable mandrel sections 228, 230
facilitate engagement with a downhole power unit 100, by
providing surfaces for receiving the application of
divergent axial tension across releasable mandrel 224
assembly to cause the releasing of threaded connections 232,
236.
[0055] Anchor 180 further includes a spring assembly 242,
which includes one or more springs disposed around lower
section 230 of release mandrel 224. The lower end of spring
assembly 242 .is secured to the release mandrel 224 by a
retaining ring 244 which is preferably threadably coupled to
lower section 230. Springs 246 are adapted to store energy
resulting from the axial compression of portions of anchor
180 when anchor 180 is set. Telescoping of compression
member 210 relative to outer mandrel 200, will cause radial
expansion of elastomeric sleeve 202, setting of barrel slip
assembly 184 and compression of springs 246.
- 21 -


CA 02480537 2004-09-02
[0056] Even though a particular embodiment of an anchor
has been depicted and described, it should be clearly
understood by those skilled in the art that other types of
anchoring devices could alternatively be used for
longitudinally securing the downhole force generator of the
present invention within a wellbore such that the downhole
force generator of the present invention may exert a force
on a well tool positioned within the wellbore.
[0057] Referring now to figure 8, therein is depicted an
exemplary pulling tool that is generally designated 250 and
that is capable of operations in the downhole force
generator of the present invention. pulling tool 250 is
depicted as being coupled to the end of threaded shaft 130
of downhole power unit 100. Pulling tool 250 has a latching
mandrel 252 that includes a reduced diameter portion 254 and
a beveled fishing nose 256 for facilitating its engagement
with a fishing neck 258 of a well tool 260 at the target
location. The latching mandrel 252 further includes a
reduced diameter portion 262 and an increased diameter
portion 264 having a ramp portion 266 therebetween. The
increased diameter portion 264 is positioned adjacent
fishing nose 256 of the latching mandrel 252.
[0058] A tubular housing 268 is disposed over latching
mandrel 252. Housing 268 includes an upper housing member
270, a lower housing member 272 and an outer housing member
274. Housing 268 also has two internal bores 276, 278. A
compression spring 280 is disposed in internal bore 276
between upper housing member 270 and lower housing member
272 to urge upper housing member 270 in a direction away
from lower housing member 272. A compression spring 282 and
a retaining ring 284 are disposed in internal bore 278.
Compression spring 282 is disposed between a shoulder of
- 22 -


CA 02480537 2004-09-02
lower housing member 272 and retaining ring 284 to urge
upper retaining ring 284 in a direction toward fishing nose
256 of the latching mandrel 252.
[0059] Pulling tool 250 includes a latching assembly 286
for automatically latching mandrel 252 of pulling tool 250
to fishing neck 258 of well tool 260 when fishing nose 256
of pulling tool 250 engages fishing neck 258. The portion
of latching assembly 286 which provides the capability of
latching pulling tool 250 to fishing neck 258 includes a
plurality of latching members 288 which are spaced around
the outer surface of latching mandrel 252. Latching members
288 are slidably positioned on latching mandrel 252 and
extend in a direction parallel to the axis of pulling tool
250. Each of the latching members 288 has an enlarged end
portion 290 which normally engages increased diameter
portion 264 of latching mandrel 252. The ends of latching
members 288 opposite the enlarged end portions 290 contact
retaining ring 284. Each of the latching members 288
includes an enlarged inner portion 292 and an enlarged outer
portion 294. Enlarged inner portion :?92 includes a ramp
portion and a shoulder that contacts a stop 296 when
latching members 288 are urged to their_ lowermost position
by compression spring 282. Enlarged outer portion 294 forms
an external shoulder that is positioned within outer housing
274.
[0060] Even though a particular embodiment of a pulling
tool has been depicted and described, it should be clearly
understood by those skilled in the art that other types of
pulling tools, such a spears, overshots and the like could
alternatively be used with the downhole force generator of
the present invention such that the down:hole force generator
- 23 -


CA 02480537 2004-09-02
of the present invention may be couple to and exert a force
on a well tool positioned within the wellbore.
[0061] An exemplary deployment and retrieval of the
downhole force generator of the present invention will now
be described with reference to figure 4-8, collectively. If
it becomes necessary to retrieve a well tool that was
previously positioned in a wellbore, the downhole force
generator of the present invention is run downhole on a
conveyance to the target location. As will be understood by
those skilled in the art, depending upon the specifics of
the operation to be performed by the downhole force
generator of the present invention, the downhole force
generator may be anchored within the wellbore then operably
coupled to the well tool or, as describe below, operably
coupled to the well tool then anchored within the wellbore.
[0062] Once the downhole force generator of the present
invention is at the target location, pulling tool 250 is
operably engaged with well tool 260. Specifically, fishing
nose 256 of latching mandrel 252 engages fishing neck 258 of
well tool 260. As fishing nose 256 moves into fishing neck
258, the ramp portions of enlarged end portions 290 of
latching members 288 first engage complimentary ramp
portions within fishing neck 258 such that latching members
288 and retaining ring 284 are pushed against spring 282.
Spring 282 is compressed which allows latching members 288
to be moved away from fishing nose 256 whereby enlarged end
portions 290 of latching members 288 are moved from
increased radius portion 264 of latching mandrel 252 up ramp
portion 266 and onto reduced radius portion 262. This
allows enlarged end portions 290 of latching members 288 to
move past the enlarged inwardly extending complimentary
portion of fishing neck 258 to a position within ffishing
- 24


CA 02480537 2004-09-02
neck 258. Once enlarged end portions 290 of latching
members 288 pass the enlarged inwardly extending portion of
fishing neck 258, spring 282 moves retaining ring 284 and
latching members 288 in the opposite direction such that
enlarged end portions 290 of latching members 288 are moved
back to their outward engaging position whereby latching
members 288 are resting on surface 264 of latching mandrel
252. Once pulling tool 250 has operably engaged well tool
260, longitudinal movement of pulling tool 250 will be
transmitted to well tool 260.
[0063] Continuing with the exemplary deployment, once
pulling tool 250 has operably engaged well tool 260, the
downhole force generator of the present invention is
anchored with the wellbore. As described above, downhole
power unit 100 is adapted to cooperate with anchor 180.
Specifically, prior to run in, engagement member 206 of
anchor 180 is coupled with connecting sub 154 of downhole
power unit 100 through pins 160. In addition, collet member
162 of connecting sub 154 of downhole power unit 100 is
positioned adjacent to annular actuation surface 238 on
upper releasable mandrel sections 228. In this
configuration, longitudinal movement of threaded shaft 130
of downhole power unit 100 moves packing assembly 186 and
barrel slip assembly 184 from their reduced diameter
conditions to their expanded diameter conditions by
engagement of outer sleeve 150 of downhole power unit 100
with axial compression member 210 of anchor 180. This
longitudinal movement exerts an axial force upon compression
member 210 due to the downward axial movement of outer
member 150 with respect to anchor 180. Accordingly, as will
be appreciated from the above discussion, actuation of motor
116 by activation assemblies 122, 124, 126, and the
resulting longitudinal movement of threaded screw 134 will
- 25 -


CA 02480537 2004-09-02
cause a relative downward movement of outer sleeve 150
relative to anchor 180. This relative downward movement
will shear shear pins 214 securing compression member 210 in
an initial, unactuated, position relative to support mandrel
assembly 182 and will thereby cause the previously described
radial expansion of elastomeric sleeve 202, setting of
barrel slip assembly 184 and compression of springs 246.
Once anchor 180 is in this set configuration, the downhole
force generator of the present invention is anchored and
longitudinally secured within the wellbore.
(0064] Once the downhole force generator of the present
invention is anchored within the wellbore, continued
longitudinal movement of threaded shaft 130 of downhole
power unit 100 transmits a longitudinal force on well tool
260 via pulling tool 250. Specifically, continued
longitudinal movement of threaded shaft 130 severs the
threaded connection between threaded shaft 130 and
connecting sub 154. As threaded shaft 130 continues
longitudinal movement, the force applied to well tool 260
increases until well tool 260 is dislodged from the
wellbore.
[0065] Once well tool 260 has been dislodged, the
downhole force generator of the present invention and well
tool 260 may be retrieved to the surface. Specifically,
downhole power unit 100 is operated to continue the
longitudinal movement of threaded shaft 130 until locating
keys 168 that are cooperatively positioned within radially
enlarged region 166 engage with annular actuation surface
240 on lower releasable mandrel sections 230 of anchor 180.
At the same time, radially enlarged region 1&4 engages
collet member 162 of connecting sub 154 of downhole power
unit 100 such that collet member 162 becomes engaged with
- 26


CA 02480537 2004-09-02
annular actuation surface 238 on upper releasable mandrel
sections 228.
[0066] Once downhole power unit 100 and anchor 180 are
positioned as described, the operation of downhole power
unit 100 to longitudinally move of threaded shaft 130 is
reversed such that threaded shaft 130 is longitudinally
moved in the opposite direction. This .Longitudinal movement
creates an axial load across release mandrel 224 between
annular actuation surfaces 238, 240. Continued longitudinal
movement will exert a sufficient axial tensile force to
separate upper releasable mandrel section 228 from lower
releasable mandrel section 230 at threaded connections 232,
236. Upon extension of release mandrel 224, compression
energy stored in spring assembly 242 is released and anchor
180 is returned to its reduced diameter configuration. Once
anchor 180 is in the reduced diameter configuratian, the
downhole force generator of the present invention and well
tool 260 may be retrieved to the surface.
[0067] While this invention has been described with
reference to illustrative embodiments, this description is
not intended to be construed in a limiting sense. Various
modifications and combinations of the illustrative
embodiments as well as other embodiments of the invention,
will be apparent to persons skilled in the art upon
reference to the description. It is, therefore, intended
that the appended claims encompass any such modifications or
embodiments.
- 27 -

Representative Drawing
A single figure which represents the drawing illustrating the invention.
Administrative Status

For a clearer understanding of the status of the application/patent presented on this page, the site Disclaimer , as well as the definitions for Patent , Administrative Status , Maintenance Fee  and Payment History  should be consulted.

Administrative Status

Title Date
Forecasted Issue Date 2013-05-28
(22) Filed 2004-09-02
(41) Open to Public Inspection 2005-03-15
Examination Requested 2009-08-19
(45) Issued 2013-05-28
Deemed Expired 2017-09-05

Abandonment History

There is no abandonment history.

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Registration of a document - section 124 $100.00 2004-09-02
Application Fee $400.00 2004-09-02
Maintenance Fee - Application - New Act 2 2006-09-04 $100.00 2006-08-03
Maintenance Fee - Application - New Act 3 2007-09-03 $100.00 2007-07-27
Maintenance Fee - Application - New Act 4 2008-09-02 $100.00 2008-08-18
Maintenance Fee - Application - New Act 5 2009-09-02 $200.00 2009-07-29
Request for Examination $800.00 2009-08-19
Maintenance Fee - Application - New Act 6 2010-09-02 $200.00 2010-08-10
Maintenance Fee - Application - New Act 7 2011-09-02 $200.00 2011-08-19
Maintenance Fee - Application - New Act 8 2012-09-04 $200.00 2012-08-27
Final Fee $300.00 2013-02-27
Maintenance Fee - Patent - New Act 9 2013-09-03 $200.00 2013-08-15
Maintenance Fee - Patent - New Act 10 2014-09-02 $250.00 2014-08-13
Maintenance Fee - Patent - New Act 11 2015-09-02 $250.00 2015-08-12
Owners on Record

Note: Records showing the ownership history in alphabetical order.

Current Owners on Record
HALLIBURTON ENERGY SERVICES, INC.
Past Owners on Record
CAMPBELL, MICHAEL
CLEMENS, JACK G.
MOORE, DARRELL W.
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.
Documents

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Document
Description 
Date
(yyyy-mm-dd) 
Number of pages   Size of Image (KB) 
Representative Drawing 2005-02-17 1 15
Cover Page 2005-02-25 1 48
Abstract 2004-09-02 1 27
Description 2004-09-02 27 1,364
Claims 2004-09-02 10 381
Drawings 2004-09-02 4 265
Claims 2012-03-06 12 401
Cover Page 2013-05-07 1 50
Representative Drawing 2013-05-14 1 15
Assignment 2004-09-02 10 413
Prosecution-Amendment 2009-08-19 3 97
Prosecution-Amendment 2011-09-07 3 116
Prosecution-Amendment 2012-03-06 14 488
Correspondence 2013-02-27 2 63